Soil on the moon can hover over the surface, and the temperature six feet deep can be more than 167 degrees C colder than the topsoil. Now researchers in Australia think they’ve solved the puzzle of moon soil’s odd behavior: nanosize particles of lunar glass.
Small bubbles of glass form on the moon when micrometeorites hit the lunar surface. Since the moon has no atmosphere to slow the projectiles, each one, no matter how tiny, “wreaks havoc,” said Paul Warren, a research geochemist at the University of California, Los Angeles, who wasn’t involved in the new study. Particles about a hundred microns wide—the size of a fine grain of beach sand—hit with enough force to melt bits of moon rock, forming tiny glass bubbles. In a new study, Marek Zbik of the Queensland University of Technology analyzed glass bubbles collected by Luna 16, the first Soviet probe to return a sample from the moon.
Using a special type of x-ray microscope, Zbik constructed 3-D images of the bubbles’ insides. Instead of containing gas, as bubbles usually do on Earth, the moon bubbles are “filled with a highly porous network of alien-looking glassy particles that span the bubbles’ interior,” Zbik said in a press statement. The researcher speculates that ongoing micrometeorite impacts release these nanoparticles, which then mix with the rest of the soil. Because of their size, the particles likely behave according to laws of quantum mechanics, which are very different from the standard rules of physics.
“Nanoparticles are so tiny, it is their size and not what they are made of that accounts for their exceptional properties,” Zbik said. It’s still unclear exactly what quantum properties the moon’s nanoglass might have. But considering that nanoparticles in general have been known to affect a substance’s electric and conductive properties, it’s possible the moon particles can explain how lunar soil develops the electrostatic charge that allows it to hover, or why the soil appears to be an unusually good insulator, Zbik proposes.